Groups > linux.kernel > #1198518

Re: [PATCH] thermal/cpu_cooling: remove local cooling state variable

From	Viresh Kumar <viresh.kumar@linaro.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH] thermal/cpu_cooling: remove local cooling state variable
Date	2015-08-03 05:20 +0200
Message-ID	<pTes9-7aU-5@gated-at.bofh.it> (permalink)
References	(4 earlier) <pRR4C-Ty-33@gated-at.bofh.it> <pS2CK-Ay-7@gated-at.bofh.it> <pS91w-1yb-9@gated-at.bofh.it> <pSkzF-1wQ-13@gated-at.bofh.it> <pSDiW-3rx-11@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On 01-08-15, 17:04, Viresh Kumar wrote:
> On 31-07-15, 08:30, Radivoje Jovanovic wrote:

> > I agree with you that this patch is trivial for the current
> > implementation since the notifier, as it is currently, will enforce
> > cpu_cooling policy change at every CPUFREQ_ADJUST which would cause
> > problems in our current implementation. In our implementation there is
> > a cpufreq driver that will also change policies during CPUFREQ_ADJUST,
> > once the request comes from the underlying FW so there would be a fight
> > who gets there first since cpu_cooling will change the policy in
> > CPUFREQ_ADJUST notifier_chain and the driver would do the same thing.

Okay, I had a detailed look this morning. cpufreq-notifier is designed
this way that policy->max can be updated by drivers.. So, that's fine.

Now coming to your problem. So, there are two users: fw and thermal,
which can affect policy->max. Now, both of them need to respect the
limits set by others and only decrease policy->max from the notifier
if it doesn't suit them.

I think it should work pretty well, unless you know you have triggered
a corner case somewhere, that I am not able to imagine.

Please let me know in case I am wrong.

-- 
viresh
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Thread

Re: [PATCH] thermal/cpu_cooling: remove local cooling state variable Viresh Kumar <viresh.kumar@linaro.org> - 2015-07-30 10:10 +0200
  Re: [PATCH] thermal/cpu_cooling: remove local cooling state variable Viresh Kumar <viresh.kumar@linaro.org> - 2015-07-31 05:20 +0200
    Re: [PATCH] thermal/cpu_cooling: remove local cooling state  variable Radivoje Jovanovic <radivoje.jovanovic@linux.intel.com> - 2015-07-31 17:40 +0200
      Re: [PATCH] thermal/cpu_cooling: remove local cooling state variable Viresh Kumar <viresh.kumar@linaro.org> - 2015-08-01 13:40 +0200
        Re: [PATCH] thermal/cpu_cooling: remove local cooling state variable Viresh Kumar <viresh.kumar@linaro.org> - 2015-08-03 05:20 +0200
          Re: [PATCH] thermal/cpu_cooling: remove local cooling state  variable Radivoje Jovanovic <radivoje.jovanovic@linux.intel.com> - 2015-08-03 21:40 +0200

csiph-web